See the following excerpt of a crash log from a release build of my app:
The problem is, after I symbolicate in Xcode using the Devices window, it only symbolicates calls from my app (Pupl), not any of the system frameworks. Any ideas as to how I can fix this?
Code Block language Hardware Model: iPhone11,8 Process: Pupl [45462] Path: /private/var/containers/Bundle/Application/3D8B69C4-8AE5-40E7-BBDF-93CC12D79E1C/Pupl.app/Pupl Identifier: com.kevinolmats.Pupl Version: 285 (1.0.1) AppStoreTools: 12A7402a AppVariant: 1:iPhone11,8:14 Code Type: ARM-64 (Native) Role: Foreground Parent Process: launchd [1] Coalition: com.kevinolmats.Pupl [2248] Date/Time: 2020-10-25 13:38:09.3546 -0700 Launch Time: 2020-10-25 13:33:01.8074 -0700 OS Version: iPhone OS 14.0.1 (18A393) Release Type: User Baseband Version: 3.00.01 Report Version: 104 Exception Type: EXC_CRASH (SIGABRT) Exception Codes: 0x0000000000000000, 0x0000000000000000 Exception Note: EXC_CORPSE_NOTIFY Triggered by Thread: 0 Application Specific Information: abort() called Last Exception Backtrace: 0 CoreFoundation 0x1884d65ac 0x1883b5000 + 1185196 1 libobjc.A.dylib 0x19c55042c 0x19c546000 + 42028 2 CoreData 0x18e58a648 0x18e460000 + 1222216 3 CoreData 0x18e58f6f4 0x18e460000 + 1242868 4 Pupl 0x100a56cac specialized WeightCategoryEditorViewModel.init(course:color:context:) + 339116 (WeightCategoryEditorViewModel.swift:30) 5 Pupl 0x100a4d7a0 closure #1 in closure #1 in closure #1 in CourseEditorWeightCategoryView.body.getter + 300960 (CourseEditorViewModel.swift:0) 6 SwiftUI 0x18ee430b0 0x18e864000 + 6156464 7 SwiftUI 0x18ed4b9c4 0x18e864000 + 5142980 8 SwiftUI 0x18edd0e90 0x18e864000 + 5688976 9 SwiftUI 0x18ee6b3f8 0x18e864000 + 6321144 10 SwiftUI 0x18ee6b6e4 0x18e864000 + 6321892 11 UIKitCore 0x18aff60d0 0x18a273000 + 14168272 12 UIKitCore 0x18aff5c8c 0x18a273000 + 14167180 13 UIKitCore 0x18aff6438 0x18a273000 + 14169144 14 UIKitCore 0x18b2bb544 0x18a273000 + 17073476 15 UIKitCore 0x18ae00400 0x18a273000 + 12112896 16 UIKitCore 0x18adef1bc 0x18a273000 + 12042684 17 UIKitCore 0x18ae22648 0x18a273000 + 12252744 18 CoreFoundation 0x188452444 0x1883b5000 + 644164 19 CoreFoundation 0x18844c858 0x1883b5000 + 620632 20 CoreFoundation 0x18844ce08 0x1883b5000 + 622088 21 CoreFoundation 0x18844c4bc 0x1883b5000 + 619708 22 GraphicsServices 0x19eed1820 0x19eece000 + 14368 23 UIKitCore 0x18adf0734 0x18a273000 + 12048180 24 UIKitCore 0x18adf5e10 0x18a273000 + 12070416 25 SwiftUI 0x18f1ad32c 0x18e864000 + 9737004 26 SwiftUI 0x18f1ad2b8 0x18e864000 + 9736888 27 SwiftUI 0x18ed26b08 0x18e864000 + 4991752 28 Pupl 0x100a1311c main + 61724 (Assignment.swift:0) 29 libdyld.dylib 0x188113e60 0x188113000 + 3680
The problem is, after I symbolicate in Xcode using the Devices window, it only symbolicates calls from my app (Pupl), not any of the system frameworks. Any ideas as to how I can fix this?
Thanks. Let’s work through this. To start, we confirm the CPU type and iOS version:Here's the full report
Code Block Code Type: ARM-64 (Native) … OS Version: iPhone OS 14.0.1 (18A393)
Now consider this:
Code Block % cd ~/Library/Developer/Xcode/iOS\ DeviceSupport % ls | cat … 14.0 (18A373) arm64e 14.0 (18A5301v) arm64e 14.0 (18A5351d) arm64e 14.0 (18A5357e) arm64e 14.0 (18A5369b) arm64e 14.0 (18A5373a) arm64e 14.1 (18A8395) arm64e 14.2 (18B5061e) arm64e 14.2 (18B5072f) arm64e …
This is a list of all the devices I’ve attached to my Mac and for which Xcode has collected symbols. There’s a bunch of iOS 14.0 beta releases in there (these start with 18A5) but I also have the iOS 14.0 GM release, 18A373. That’s really close to iOS 14.0.1, so we’re going to work with that.
Now let’s consider frame 3 from the Last Exception Backtrace section, which is an example of what we want to symbolicate:
Code Block 3 CoreData 0x18e58f6f4 0x18e460000 + 1242868
The crash is at address 0x18e58f6f4 which is 1242868 bytes from the start of the CoreData framework, 0x18e460000. In the crash report we can find the CoreData framework in the Binary Images section:
Code Block 0x18e460000 - 0x18e7d1fff CoreData arm64e <e6bbd2ec59f6316a9368b53ba3da38ae> /System/…
This says:
The framework was loaded at 0x18e460000 and extends to 0x18e7d1fff.
Its name is CoreData.
It was compiled for arm64e (a more secure variant of arm64 that we use in all our system frameworks).
Its binary UUID is e6bbd2ec59f6316a9368b53ba3da38ae.
Its path is, well, obvious, so I elided it (-: The path is often relevant on macOS where frameworks can be loaded from all sorts of places.
Code Block % dwarfdump --uuid 14.0\ \(18A373\)\ arm64e/Symbols/System/Library/Frameworks/CoreData.framework/CoreData UUID: E6BBD2EC-59F6-316A-9368-B53BA3DA38AE (arm64e) 14.0 (18A373) arm64e/Symbols/System/Library/Frameworks/CoreData.framework/CoreData
Interesting. The binary UUID matches our crash report, so we’re not guessing here: Our symbolication results will be precise. It’s time to go for it:
Code Block % atos \ -o 14.0\ \(18A373\)\ arm64e/Symbols/System/Library/Frameworks/CoreData.framework/CoreData \ -l 0x18e460000 \ 0x18e58f6f4 … _sharedIMPL_setvfk_core (in CoreData) + 192
Let’s break that down:
atos is a tool that’ll map addresses to symbols. See its man page for detailed info on how to use it.
The -o line tells atos what image to look at.
-l 0x18e460000 specifies the load address for that image.
0x18e58f6f4 is the address to symbolicate.
You should repeat this process for frame 2 of your backtrace.
Note There’s no point doing it for frames 1 through 0 because the presence of the Last Exception Backtrace section makes it clear that these are objc_exception_throw and __exceptionPreprocess respectively.
As to what this error actually means, something has gone wrong in a CoreData managed object setter. This isn’t really my field, so I don’t have any ready answers for you. Once you’ve symbolicated frames 4 through 2 you can start a new thread, requesting help from CoreData experts by tagging it with CoreData.
Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@apple.com"
